Sure, sorry.
size of tank? 12 Gallons
Temperature of tank? Unsure, but between 10 and 15
What other fish do you have? types and numbers 1 other goldfish
what do you feed and how often? Twice a day, three flakes per goldfish
Going to need some test results?
PH? 7.2
Ammonia? 0-0.25
Nitrite? 0
Nitrate? 10
How long has the tank been up and running? 2 weeks
what if anything have you added that is new to the tank? Some plant fertilizer and some slate
when was the last time you did a water change, how much...% or total volume...
Saturday, 20%
Hope that helps. The fish that died kept rolling over on its side or upside down before it died- that's what made me think it was swimbladder. The other goldfish is still hanging around the gravel